JPH03252411A - Thermosetting resin composition - Google Patents

Abstract

PURPOSE:To provide the subject composition having the mechanical properties not deteriorated even at high temperature and having excellent heat resistance and processability by compounding a specific aromatic polyamide oligomer and a maleimide derivative. CONSTITUTION:The objective composition comprises (A) an aromatic polyamide oligomer of the formula [R1, R2 are divalent aromatic groups; A, B are aliphatic or aromatic unsaturated groups (A=B is possible); n is 1-15] and (B) a maleimide derivative (preferably phenyl maleimide, aromatic dimaleimide or aromatic polymaleimide).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a heat-resistant synthetic resin, and particularly to a heat-resistant thermosetting resin composition with excellent processability.

[Prior Art] As the demands of the plastics industry become more sophisticated, industrial materials with special properties are required, and this trend is rapidly developing as technology becomes more sophisticated.

The demand for improved heat resistance is felt in plastics, films, fibers,
The aim is to add heat resistance to industrial materials used in fields that require heat resistance, such as laminates, laminates, and adhesives, to expand the market, and to expand into a wide range of new fields with new functions. Aromatic polyamide,
A group of synthetic resins called engineering plastics, such as polyimide, polysulfone, and polyphenylene oxide, have already been developed and are being industrially produced as Plus Deck, which has new functions different from conventional synthetic resins, opening up new fields of demand. One of these is aromatic polyamide, known under the name aramid.

Examples of aromatic polyamides include polyparaphenylene terephthalamide (product name: Kevlar) and polymetaphenylene isophthalamide (product name:
Nomex or HT-1) is a typical type.

All of these polyamides are essentially classified as thermoplastic synthetic resins.

Generally, they have a high melting point, and the difference between the melting point and the thermal decomposition temperature is small, or in some cases reversed, so melt molding is difficult or impossible depending on the structure. On the other hand, a type of polyamide in which an oligomer is prepared as a precursor and then thermally cured has not yet been proposed.

The reason why there was no thermosetting aromatic polyamide was as follows.
- This is thought to be because the melting point of the thermoplastic synthetic resin was sufficiently higher than that of conventional thermoplastic synthetic resins, and the introduction of unsaturated bonds was considered to have a high risk of causing undesirable gelation during the molding process.

On the other hand, it is also well known that one of the typical heat-resistant resins is a polymer formed by adding amino groups to unsaturated bonds in the Michael reaction of dimaleimides and aromatic diamines ( ``Kelimide'' manufactured by Rhône-Boulin, France).

However, when attempting to homopolymerize maleimides, the polymerization reaction is too intense at high temperatures, making it difficult to obtain useful polymers.

[Problems to be solved by the invention] Aromatic polyamides are relatively stable even at considerably high temperatures, have excellent electrical properties (1) mechanical strength, and have high chemical stability and are excellent heat-resistant polymers. .

The purpose of the present invention is to develop an aromatic polyamide-based resin that has improved moldability, mechanical strength and chemical stability at high temperatures without losing the excellent kneading properties of aromatic polyamide. This is what I did.

1. Means for Solving the Problem] The present inventors found that when molding as a molding material or as a laminate, it has a relatively low melting point, can be molded into a desired shape under heat and pressure, and is In order to obtain an aromatic polyamide oligomer that can be cured under mild conditions and has sufficient heat resistance, mechanical strength, and chemical stability after curing, unsaturated alcohol or unsaturated phenol, aromatic diamine, and aromatic An aromatic polyamide oligomer having a radically polymerizable unsaturated group was obtained by reacting dicarboxylic acid cybaride in the presence of a hydrogen halide acceptor.

It was discovered that this oligomer can be cured in the presence of a radical-generating catalyst, and that this cured aromatic polyamide has the above-mentioned excellent properties. To improve the speed and to lower the melting point of the mixture before curing by selecting the mixing ratio of both, and to obtain a molded product having sufficient heat resistance, mechanical strength and chemical stability after curing. I was able to complete the present invention knowing that such desirable improvements can be made.

The aromatic polyamide oligomer of the present invention having an unsaturated group at the end or inside the carbon chain can be represented by the following reaction formula, for example.

(Unsaturated alcohol) (Aromatic diamine) (Aromatic dicarboxylic acid civalide) '-OCH, CH=CH1 (Aromatic polyamide oligomer) -----...[II] Smoothly progresses the reaction of [II] above Therefore, an acceptor for by-produced hydrogen chloride is required, and it is convenient to use an aliphatic tertiary amine or a caustic alkali.

In this case, n is about 1 or 615, preferably 3 to 7.
This value is advantageous from the viewpoint of ease of moldability, and polymerization at this stage is not particularly necessary.

This reaction is generally carried out by mixing amines in an aqueous phase and acid chlorides in an inert organic solvent that does not dissolve in water to perform an interfacial polycondensation reaction, or by dissolving both in an inert organic solvent and condensing them at low temperatures. It can be carried out by low temperature solution polycondensation reaction.

Precursors of organic residues having an unsaturated group at the end or inside of the carbon chain that can be used in the present invention include allyl alcohol,
Crotyl alcohol, methyl vinyl carbinol, propargyl alcohol, 2-butyn-1-ol, 3-butyn-2-ol, 3-butyn-1-ol, 5-norbornenemethanol, cinnamyl alcohol, 0-9m-
or p-isopropenylphenol, o-, m- or p-vinylphenol, and the like.

Further, as the aromatic dicarboxylic acid civalide that can be used in the present invention, dichlorides of aromatic dibasic acids are convenient, and representative examples include terephthalic acid dichloride, isophthalic acid dichloride, phthalic acid dichloride, or mixtures thereof.

With phthalic acid dichloride, the heat resistance of the aramid after curing is insufficient, and when terephthalic acid dichlorite is used, the heat resistance is sufficient, but the resulting aromatic polyamide oligomer has a high melting point, making it difficult to handle. From a practical standpoint, isophthalic acid dichloride best meets the purpose of the present invention.

Examples of the aromatic diamine include metaphenylene diamine and 4.4°-diaminodiphenylmethane.

4.4'-diaminodiphenylpropane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 4.4
'-Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3.3'-diaminodiphenyl sulfone, 4.4'-diaminodiphenyl sulfone, dianisidine, 2.4-4ylene diamine, 2.4/2.
6-)-Lylene diamine mixture, 1,3-bis(3-
Aminophenokidine benzene and the like can be used, and two or more types can be used in combination.

Since this synthesis reaction proceeds relatively stoichiometrically, enter the desired value into D in the above formula [1] and calculate (the same calculation can be done even if it is not allyl alcohol), and then the required amount of unsaturated alcohol or unsaturated phenol;
It is sufficient to react the aromatic diamine and the aromatic dicarboxylic acid civalide, and if precise adjustment is required, the molar ratio can be determined by a simple test.

As already explained, the composition of the aromatic polyamide oligomer obtained by this reaction can be easily selected and can be molded at a temperature of 200° C. or lower.

The aromatic polyamide oligomer having an unsaturated group at the end or inside of the carbon chain synthesized according to the present invention can be cured in combination with a radical generating catalyst, making it possible to significantly improve heat resistance.

Maleimides used in combination with aromatic polyamide oligomers can be divided into the following three types.

(il phenylmaleimides (ii) dimaleimides synthesized from aromatic diamine and maleic anhydride The types of aromatic diamines mentioned above are used.

[1ii) Polymaleimide synthesized from aniline-formaldehyde condensate and maleic anhydride Furthermore, it is also possible to use a mixture of fi), fii), (ii, and il).

) 1 Nylmaleimide has a low melting point and is a phase with aromatic polyamide oligomer? Although there is a wide range of properties, they are somewhat lacking in heat resistance, and dimaleimides made from aromatic diamines are used as a material.

Examples of these include N-phenylmaleimide, N-(
0-chlorophenyl)maleimide, N,N'-diphenylmethane bismaleimide, N,N'-diphenyl ether bismaleimide, N,N'-paraphenylene bismaleimide, N.

N'-(2-methylmetaphenylene)bismaleimide, N,N'-metaphenylenebismaleimide, N,
Examples include N'-(3,3'-dimethyldiphenylmethane)bismaleimide, N,N'-(3,3°-diphenylsulfone)bismaleimide, and maleimides of aniline-formaldehyde condensates.

The aromatic polyamide oligomer of the present invention having a polymerizable unsaturated group at the end or inside the carbon chain generally has a slow curing speed, and even if a radical generator is used as a catalyst, it cannot be heated to a high temperature for a relatively long period of time. Although required, the curing speed can be improved by incorporating maleimide derivatives.

Furthermore, it has the effect of improving the moldability (lowering the melting point) of the composition containing maleimide before curing, and can be processed at low pressure.

The blending ratio of aromatic polyamide oligomer and maleimide derivative is based on 100 parts by weight of aromatic polyamide oligomer.
10 to 200 parts by weight of maleimide derivative, preferably 10
~100 parts by weight.

When the amount of maleimide added is 10 parts by weight or less, the heat resistance is good, but the melting point decreases so much that the effect of improving moldability is reduced. In addition, even if the amount exceeds 200 parts by weight, the melting point remains almost constant, and not only is no further melting point drop observed, but the IIT thermal properties of the molded product decrease, and at the same time, the polymerization reaction becomes more intense, making it difficult to control. There is a problem.

The mixture of aromatic polyamide oligomer and maleimide according to the present invention can be cured in combination with a radical photobiocatalyst, making it possible to significantly improve heat resistance.

There is no need to limit the radical generating catalyst, but when the molding temperature is 100° C. or higher, a so-called high-temperature decomposition type catalyst, such as a dicumyl peroxide type, is used.

The appropriate amount used is 1 to 3 phr.6 In addition, the combined use of a monomer that can copolymerize with the unsaturated bonds of the oligomer is possible when the monomer dissolves the aromatic polyamide oligomer and maleimide derivative under the curing reaction conditions. In particular, when n in the formula [IJ] is a small value, the range of application is wide.

It goes without saying that the aromatic polyamide oligomer having an unsaturated group according to the present invention can be used in combination with a reinforcing agent, a filler mold release agent, a coloring agent, a polymer, etc., if necessary, during curing.

Next, in order to aid understanding of the present invention, Examples will be shown below.

[Example] [Oligomer I] 500 ml containing reflux condenser, dropping funnel, thermometer, stirrer
20.3 g (0.1 mol) of isophthaloyl chloride and 100 g of dimethylformamide (DMF) are placed in a 0 m 12 four-necked separable flask and cooled to below 10°C.

Next, 1.94 g of allyl alcohol <0.0334 mol), 3.4°-diaminodiphenyl ether (3,
4°-DAPE) 16.67g (0,0834 mol)
, triethylamine 20.5g (0,203 mol)
, 80 g of DMF were weighed and mixed and added dropwise to the reaction flask.

After the dropping is completed, the dropping funnel is washed with 20 g of DMF, and the washing liquid is added to the reaction flask. During that time, the reaction temperature was 10℃
Keep below.

After the addition is complete, stirring is continued for 2 hours while keeping the temperature of the reaction mixture below 10°C.

The reaction mixture is then gradually added to a large volume of vigorously stirred water to precipitate crystals. The precipitated crystals were filtered with suction, washed with water and dried to obtain oligomer [13].

<Synthesis Examples 2 to 6> Operations were carried out under the same conditions as in Synthesis Example 1 except that the formulations shown in Table 1 were used.

(Left below) (Example J) 1 part by weight of the oligomer [1] synthesized in Synthesis Example 1, 0.175 parts by weight of N-phenylmaleimide, and 1.18 parts by weight of a 2% acetone solution of dicumyl peroxide were placed in a test tube. and mixed evenly.

Next, the temperature was gradually raised and heated at 80° C. for 1 hour to remove acetone and dry. After drying, the temperature was raised to 160°C and cured for 2 hours. Further increase the temperature to 200℃.

After 5 hours of curing, an amber-colored, tough, insoluble, and infusible bulk polymer was obtained.

The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in the air at a heating rate of 10°C/min.
) became like this.

95% weight retention temperature 366°C 90% weight retention temperature 422°C 500°C Weight retention 77.6% (Example 2) Oligomer synthesized in Synthesis Example 1 [111 parts by weight, 1 part by weight of N-phenylmaleimide, The same operation as in Example 1 was carried out except that 2 parts by weight of a 2% acetone solution of dicumyl peroxide was used.

The resulting polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
2) became like this.

95% weight retention temperature 350°C 90% weight retention temperature 376°C 500°C Weight retention 691% (Example 3) Oligomer synthesized in Synthesis Example 1 [I] 1 part by weight, N,
The same procedure as in Example 1 was carried out except that 1 part by weight of N"-diphenylmethane bismaleimide and 2 parts by weight of 2% dicumyl peroxide dissolved in acetone were used.

The obtained polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
3) became like this.

95% weight retention temperature 420°C 90% weight retention temperature 456°C 500°C Weight retention 814% (Example 4) Oligomer [11] synthesized in Synthesis Example 2 1 part by weight, N,
The same operation as in Example 1 was performed except that 1 part by weight of N'-diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

The obtained polymer was crushed in a mortar and thermogravimetrically analyzed in air at a heating rate of 10°C/min.
4) It became like this.

95% weight retention temperature 320°C 90% weight retention temperature 396°C 500°C Weight retention 73.4% (Example 5) Oligomer synthesized in Synthesis Example 3 [■] 1 part by weight, N, N
The same operation as in Example 1 was carried out except that 1 part by weight of -diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

95% weight retention temperature 388°C 90% weight retention temperature 434°C 500°C Weight retention 778% (Example 6) Oligomer synthesized in Synthesis Example 4 [■] 1 part by weight, N,
The same operation as in Example 1 was performed except that 1 part by weight of N'-diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

95% weight retention temperature 401°C 90% weight retention temperature 444°C 500°C Weight retention 776% (Example 7) Oligomer [V] synthesized in Synthesis Example 5 1 part by weight, N, N
The same operation as in Example 1 was carried out except that 1 part by weight of -diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

95% weight retention temperature 414°C 90% weight retention temperature 453°C 500°C Weight retention 81.8% (Example 8) Oligomer synthesized in Synthesis Example 6 [■] 1 part by weight, N,
The same operation as in Example 1 was performed except that 1 part by weight of N'-diphenylmethane bismaleimide and 2 parts by weight of a 2% acetone solution of dicumyl peroxide were used.

95% weight retention temperature 410°C 90% weight retention temperature 447°C 500°C Weight retention 79.5% (Example 9) 100 parts by weight of oligomer [I] synthesized in Synthesis Example 1, N
, a glass cloth was immersed in a solution of 100 parts by weight of N'-diphenylmethane bismaleimide and 3 parts of dicumyl peroxide dissolved in 200 parts of DMF, and then heated at 100°C for 1 hour.
A prepreg was prepared by drying for a while. After that, several sheets of this prepreg were stacked together under a pressure of 30 kg/cm",
After heating and pressurizing at a temperature of 160°C for 1 hour, post-curing was performed at 200°C for 5 hours to obtain a laminate.

The bending strength of this laminate was 55 kg/m2 at 25°C and 46 kg/m2 at 200°C. The bending strength after heating at 230℃ for 200 hours is 2.
It was 52 g/fflTM'' at 5°C.

(Reference Example 1) A composition in which a maleimide is added to an aromatic polyamide oligomer has a significantly lower melting point and is easier to process.

As an example, Table 2 shows the melting points of N-phenylmaleimide and the oligomer [I] obtained in Synthesis Example 1 at various mixing ratios. It was possible to provide a thermosetting polyamide resin with excellent heat resistance that does not lose its properties and whose mechanical properties do not deteriorate even at high temperatures, and a resin composition that can be hardened with particularly improved curability and processability. .

[Brief explanation of drawings]

FIG. 1 shows the results of thermogravimetric analysis of the cured resin compositions of Examples 1-4.

Claims (3)

[Claims] (1) (a) A thermosetting resin composition comprising an aromatic polyamide oligomer having an unsaturated group at the end or inside of a carbon chain and represented by the general formula [I] and (b) a maleimide derivative. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ ... [I] [However, in the formula, R_1 and R_2 are divalent aromatic groups, A
and B are aliphatic or aromatic unsaturated groups (A=B may also be acceptable), and n represents a number from 1 to 15. ] (2) The maleimide derivative according to claim 1, wherein the maleimide derivative is at least one of phenylmaleimide, aromatic dimaleimide, and aromatic polymaleimide. (3) In claim 1, polyamide oligomer 1
A thermosetting resin composition in which the maleimide derivative is contained in an amount of 10 to 200 parts by weight based on 00 parts by weight.